Mars

The InSight Mars lander was successfully launched on Saturday morning, by an Atlas V rocket taking off from Vandenberg Air Force Base in California. It will gather data on Mars' interior.

The reactor could keep the lights on during long-duration missions far from Earth.

The heat shield, made of material that is as light as balsa wood but can withstand temperatures of nearly 4,000 degrees Fahrenheit, broke during testing earlier this month.

Musk's successful rocket launch is a step on the ambitious road to Mars; as with our adventurous ancestors, where we might go seems to be limited only by our imagination, says Marcelo Gleiser.

It captured images that show some of the key regions NASA's robot has explored since 2012.

The size and accessibility of these ice sheets, as well as the fact that they're made of relatively clean water, could be an important resource for astronauts traveling to Mars.

Take five minutes of your day, watch this amazing video of the birth of a new island in Tonga, and let its story and science knock you to the floor, says astrophysicist Adam Frank.

"Space Policy Directive 1," which Trump signed Monday, sees Mars as the ultimate destination. But analysts wonder whether money will follow to support the plan.